<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'test3.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> <script src="js/jquery-2.1.1.min.js"></script> <script> //this對象是指在運行時期基於執行環境所綁定的 //this老是指向調用者 var k=10; function test(){ this.k=20; } //alert(test.k); //test()函數未執行,輸出undefined //調用test()至關於調用window.test(),test內部的this指向window對象,改變了全局變量的k的值 test(); alert(k); //20至關於widow.k,輸出20,window通常省略 </script> </head> <body> This is my JSP page. <br> </body> </html>